arm64: KVM: hypervisor initialization code

Provide EL2 with page tables and stack, and set the vectors
to point to the full blown world-switch code.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 107 insertions, 0 deletions

diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
new file mode 100644
index 000000000000..ba84e6705e20
--- /dev/null
+++ b/arch/arm64/kvm/hyp-init.S
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2012,2013 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/assembler.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_mmu.h>
+
+        .text
+        .pushsection    .hyp.idmap.text, "ax"
+
+        .align  11
+
+ENTRY(__kvm_hyp_init)
+        ventry  __invalid               // Synchronous EL2t
+        ventry  __invalid               // IRQ EL2t
+        ventry  __invalid               // FIQ EL2t
+        ventry  __invalid               // Error EL2t
+
+        ventry  __invalid               // Synchronous EL2h
+        ventry  __invalid               // IRQ EL2h
+        ventry  __invalid               // FIQ EL2h
+        ventry  __invalid               // Error EL2h
+
+        ventry  __do_hyp_init           // Synchronous 64-bit EL1
+        ventry  __invalid               // IRQ 64-bit EL1
+        ventry  __invalid               // FIQ 64-bit EL1
+        ventry  __invalid               // Error 64-bit EL1
+
+        ventry  __invalid               // Synchronous 32-bit EL1
+        ventry  __invalid               // IRQ 32-bit EL1
+        ventry  __invalid               // FIQ 32-bit EL1
+        ventry  __invalid               // Error 32-bit EL1
+
+__invalid:
+        b       .
+
+        /*
+         * x0: HYP boot pgd
+         * x1: HYP pgd
+         * x2: HYP stack
+         * x3: HYP vectors
+         */
+__do_hyp_init:
+
+        msr     ttbr0_el2, x0
+
+        mrs     x4, tcr_el1
+        ldr     x5, =TCR_EL2_MASK
+        and     x4, x4, x5
+        ldr     x5, =TCR_EL2_FLAGS
+        orr     x4, x4, x5
+        msr     tcr_el2, x4
+
+        ldr     x4, =VTCR_EL2_FLAGS
+        msr     vtcr_el2, x4
+
+        mrs     x4, mair_el1
+        msr     mair_el2, x4
+        isb
+
+        mov     x4, #SCTLR_EL2_FLAGS
+        msr     sctlr_el2, x4
+        isb
+
+        /* MMU is now enabled. Get ready for the trampoline dance */
+        ldr     x4, =TRAMPOLINE_VA
+        adr     x5, target
+        bfi     x4, x5, #0, #PAGE_SHIFT
+        br      x4
+
+target: /* We're now in the trampoline code, switch page tables */
+        msr     ttbr0_el2, x1
+        isb
+
+        /* Invalidate the old TLBs */
+        tlbi    alle2
+        dsb     sy
+
+        /* Set the stack and new vectors */
+        kern_hyp_va     x2
+        mov     sp, x2
+        kern_hyp_va     x3
+        msr     vbar_el2, x3
+
+        /* Hello, World! */
+        eret
+ENDPROC(__kvm_hyp_init)
+
+        .ltorg
+
+        .popsection